We compare the structure and growth modes of two series of nanocrystalline Ni/Pt multilayers deposited on glass, Si, and polyimide substrates by electron-beam evaporation at room temperature (40 °C) and at 200 °C. X-ray diffraction patterns are recorded in order of the quality of the layering to be examined. The morphology of the films is studied by atomic force microscopy. The roughness of the samples is found to depend on the substrate and the total thickness, following a power law. The crystal structure, the shape of the crystallites, and the layering of the samples were determined by transmission electron microscopy. Differences in the shape of the crystallites and the surface morphology between the two series of samples are observed and they are understood within the framework of structural zone models. Finally, it is demonstrated the large stability of the multilayer structure for a period of at least 12 years.